The present invention relates to a pen type printing apparatus such as a graphic printer or an alpha-numeric printer and, particularly, to a pen type printing apparatus which permits an easy confirmation of the printing state, stabilizes feeding of the printing paper and which has reduced size and weight so as to be suitable for use as printing apparatus used with a personal computer, various measuring systems and so forth.
Generally, in thermal printers, ink jet printers or the like, it is comparatively easy to reduce the weight of the carriage. In these printers, the data are printed in the form of fine dots, so that it is undeniable that the quality of printing is inferior to that of the pen type recorder in which the data are printed in the form of lines actually drawn by pens or the like. The thermal printer also has a disadvantage that the printing can be made only on a heat-sensitive paper. In addition, in ink jet printers, it is necessary to employ a comparatively complicated mechanism including a pump or the like to recycle the printing ink.
Under these circumstances, there is an increasing demand for a pen type printing apparatus having a carriage of a reduced size and weight.
It is also to be pointed out that printers hitherto proposed often suffer a common problem of feeding the recording paper in an unstable manner, as will be described later in more detail with reference to the drawings.